The invention relates to improvements in apparatus for regulating the flow of fluids, such as liquid and/or gaseous media. More particularly, the invention relates to improvements in apparatus for regulating the flow of gaseous or liquid media between separate compartments which are communicatively connected to each other to permit the fluid medium to flow between them along one or more predetermined paths.
It is well known to apply layers of adhesive and/or coloring material to running webs of paper, plastic or textile material, metallic foil or other substrates. Reference may be had to the aforementioned commonly owned copending patent application Ser. Nos. 103,421 and 111,403. As a rule, the layers are applied by means of nozzles having elongated slit-shaped orifices whose length corresponds to the width of a running web that is to be provided with a layer of fluid medium. The nozzle constitutes the outlet of a housing which can be said to act as a distributor of flowable material and receives such material by way of a supply conduit which is connected to a suitable source. The manner in which the flowable material is distributed in the housing on its way toward the orifice of the nozzle is not entirely satisfactory, especially if the orifice is long, because the rate of fluid flow to different portions of the orifice is affected by pressure losses and for a number of other reasons. Therefore, it is customary to regulate the flow of fluid medium from the inlet of the housing toward the orifice of the nozzle so as to ensure a predictable distribution of the fluid medium on the adjacent web. Heretofore known proposals to regulate the flow of fluid medium to different portions of an elongated slit-shaped orifice are unsatisfactory for a number of reasons including high cost, lack of versatility, unpredictable distribution, excessive bulk and/or others.